JPWO2012029099A1 - Heat pump device, heat pump system, and control method for three-phase inverter - Google Patents

Abstract

An object of the present invention is to efficiently heat the refrigerant staying in the compressor. The phase switching unit 19 switches and outputs the phase θ1 and the phase θ2 that is substantially 180 degrees different from the phase θ1 in synchronization with the carrier signal. The adder 20 adds the phase θplus of 60 times n times to the phase output by the phase switching unit 19 and outputs the voltage command phase θ. The high-frequency AC voltage generator 13 generates and outputs three-phase voltage command values Vu *, Vv *, and Vw * based on the voltage command phase output from the adder 20. The PWM signal generation unit 17 compares the three-phase voltage command values Vu *, Vv *, and Vw * output from the high-frequency AC voltage generation unit 13 with the carrier signal, and corresponds to the switching elements 18a to 18f of the inverter 9. Are generated, and each generated drive signal is output to the corresponding switching element of the three-phase inverter, thereby causing the inverter 9 to generate a high-frequency AC voltage.

Description

  The present invention relates to a method for heating a compressor used in a heat pump apparatus.

  Patent Document 1 describes that when the amount of liquid refrigerant staying in the compressor exceeds a predetermined value, a weak high-frequency phase loss current is applied to the motor winding to warm the motor winding. Thereby, the liquid compression by the operation start in the state in which the liquid refrigerant stagnated in the compressor is prevented, and the compressor is prevented from being damaged.

  Patent Document 2 describes that the direction of the current flowing in the stator coil of the motor is periodically reversed by controlling the ON / OFF cycle of the switching element. As a result, heat is generated not only due to resistance loss but also due to hysteresis loss, so that sufficient preheating can be performed with low current consumption, thereby improving power efficiency.

JP-A-8-226714 Japanese Patent Laid-Open No. 11-159467

  In the technique described in Patent Document 1, windings in which no current flows are generated because a phase loss current flows, and the compressor cannot be heated uniformly. Further, when an inverter is used to pass a phase loss current to a permanent magnet synchronous motor having a salient pole ratio, the winding inductance depends on the rotor position. For this reason, current may flow in all phases depending on the rotor position, so that it is difficult to flow an open phase current.

  In the technique described in Patent Document 2, any one of the switching elements having one end connected to the power supply side is repeatedly turned on / off a predetermined number of times during a predetermined time. At the same time, any two switching elements whose one ends are connected to the ground side are turned on for the predetermined time, and then the current flowing through the stator coil is reversed. For this reason, the frequency of the current flowing through the winding cannot be increased, and there is a limit to the occurrence of iron loss due to the increased frequency, so that the efficiency cannot be improved. In addition, noise is generated.

  An object of the present invention is to efficiently heat the refrigerant staying in the compressor.

The heat pump device according to this invention is
A compressor having a compression mechanism for compressing the refrigerant;
A motor for operating the compression mechanism of the compressor;
A three-phase inverter that applies a predetermined voltage to the motor, and a three-phase inverter that is configured by connecting a series connection circuit of two switching elements in parallel for three phases; and
An inverter control unit for controlling the three-phase inverter;
The inverter control unit
A phase switching unit that switches and outputs a phase θ1 and a phase θ2 that is substantially 180 degrees different from the phase θ1 in synchronization with a reference signal having a predetermined frequency;
An adder that outputs a phase θ3 by changing a value n that is an integer greater than or equal to 0 every predetermined time, and adding a phase θplus of n times 60 degrees to the phase output by the phase switching unit;
A voltage generator that generates and outputs three-phase voltage command values Vu *, Vv *, and Vw * based on the phase θ3 output from the adder;
The three-phase voltage command values Vu *, Vv *, Vw * output from the voltage generator are compared with the reference signal to generate six drive signals corresponding to the switching elements of the three-phase inverter, A drive signal generation unit that generates a high-frequency AC voltage in the three-phase inverter by outputting each generated drive signal to a corresponding switching element of the three-phase inverter is provided.

The heat pump device according to the present invention generates a drive signal based on the phase θ1 and the phase θ2 that are switched and output in synchronization with the carrier signal. Therefore, a high-frequency voltage with high waveform output accuracy can be generated, and the refrigerant staying in the compressor can be efficiently heated while suppressing the generation of noise.
In addition, the heat pump device according to the present invention generates a drive signal based on the phase θ3 obtained by adding the phase θplus changed every predetermined time to the phase θ1 or the phase θ2. Therefore, even in the case of an IPM motor, it is possible to appropriately heat the refrigerant staying in the compressor regardless of the stop position of the rotor.
In particular, since the phase θplus is an integer multiple of 60 degrees, motor noise, motor shaft vibration, and the like due to current waveform distortion and the like can be suppressed.

1 is a diagram showing a configuration of a heat pump device 100 according to Embodiment 1. FIG. The figure which shows the input-output waveform of the PWM signal generation part 17. FIG. 6 is a flowchart showing the operation of the inverter control unit 11. FIG. 5 shows a configuration of a heat pump device 100 according to a second embodiment. 6 is a timing chart when the phase switching unit 19 alternately switches between the phase θ1 and the phase θ2 at the timing of the top and bottom of the carrier signal. Explanatory drawing of the change of the voltage vector shown in FIG. The timing chart when the phase switch part 19 switches phase (theta) 1 and phase (theta) 2 alternately by the timing of the bottom of a carrier signal. Explanatory drawing of the rotor position (rotor stop position) of an IPM motor. The figure which shows the electric current change by a rotor position. FIG. 6 shows a configuration of a heat pump device 100 according to Embodiment 3. The figure which shows the applied voltage at the time of changing (theta) plus with progress of time. Explanatory drawing of an intermediate voltage. The timing chart when (theta) plus is 45 degree | times when the phase switch part 19 switches phase (theta) 1 and phase (theta) 2 alternately by the timing of the top and bottom of a carrier signal. The figure showing the electric current which flows into each phase of UVW of a motor when (theta) plus is 0 degree | times, 30 degree | times, and 60 degree | times. The figure which shows the electric current waveform at the time of energization phase switching. The figure which shows the relationship between (theta) plus and the amplitude A which the amplitude output part 16 outputs. The figure which shows a mode that a current waveform is improved by changing the amplitude A according to switching of (theta) plus. The figure which shows the drive circuit 21 which receives each PWM signal from the PWM signal generation part 17, and drives each switching element 18 of the inverter 9. The figure which shows the relationship between (theta) plus and generation | occurrence | production of a charge pulse. FIG. 6 is a circuit configuration diagram of a heat pump device 100 according to a fourth embodiment. The Mollier diagram about the state of the refrigerant | coolant of the heat pump apparatus 100 shown in FIG.

Embodiment 1 FIG.
In the first embodiment, a basic configuration and operation of the heat pump apparatus 100 will be described.

FIG. 1 is a diagram illustrating a configuration of a heat pump device 100 according to the first embodiment.
The heat pump device 100 includes a refrigeration cycle in which a compressor 1, a four-way valve 2, a heat exchanger 3, an expansion mechanism 4, and a heat exchanger 5 are sequentially connected by a refrigerant pipe 6. Inside the compressor 1, a compression mechanism 7 that compresses the refrigerant and a motor 8 that operates the compression mechanism 7 are provided.
In addition, an inverter 9 that applies a voltage to the motor 8 to drive is provided with a bus voltage detector 10 that is electrically connected to the motor 8 and detects a bus voltage that is a power supply voltage of the inverter 9. The control input terminal of the inverter 9 is connected to the inverter control unit 11. The inverter control unit 11 includes a compressor heating permission unit 12 (detection unit), a high-frequency AC voltage generation unit 13, an integrator 14, a rotation speed command output unit 15, an amplitude output unit 16, and a PWM signal generation unit 17 (drive signal generation unit). ).

The inverter 9 is a three-phase inverter in which series connection circuits of two switching elements (18a and 18d, 18b and 18e, 18c and 18f) are connected in parallel for three phases. The inverter 9 is switched by the PWM signals UP, VP, WP, UN, VN, and WN (drive signals) sent from the inverter control unit 11 in accordance with the switching elements (UP is 18a, VP is 18b, WP is 18c, UN drives 18d, VN drives 18e, and WN drives 18f).
When the inverter control unit 11 determines that the compressor heating permission unit 12 is in a state where the liquid refrigerant has accumulated in the compressor 1 (a state in which the refrigerant has stagnated), the inverter high-frequency AC voltage generation unit 13 causes the motor 8 to Command values Vu *, Vv * and Vw * for the applied voltage are obtained. Then, the PWM signal generator 17 generates a PWM signal based on the voltage command values Vu *, Vv *, and Vw * obtained by the high-frequency AC voltage generator 13.

A method for generating a PWM signal by the PWM signal generation unit 17 will be described.
FIG. 2 is a diagram illustrating input / output waveforms of the PWM signal generation unit 17.
For example, the voltage command values Vu *, Vv *, and Vw * are defined as cosine waves (sine waves) whose phases are different by 2π / 3 as shown in equations (1) to (3). Where A is the amplitude of the voltage command value, and θ is the phase of the voltage command value.
(1) Vu * = Acos θ
(2) Vv * = Acos (θ− (2/3) π)
(3) Vw * = Acos (θ + (2/3) π)
The high-frequency AC voltage generator 13 includes a voltage phase command θ obtained by integrating the rotational speed command ω * output from the rotational speed command output unit 15 by the integrator 14, and the amplitude output from the amplitude output unit 16. Based on A, the voltage command values Vu *, Vv *, Vw * are calculated by the equations (1) to (3), and the calculated voltage command values Vu *, Vv *, Vw * are sent to the PWM signal generation unit 17. Output. The PWM signal generation unit 17 compares the voltage command values Vu *, Vv *, and Vw * with a carrier signal (reference signal) having a predetermined frequency and an amplitude Vdc / 2, and determines the PWM signal UP, VP, WP, UN, VN, WN are generated. Vdc is a bus voltage detected by the bus voltage detector 10.
For example, when the voltage command value Vu * is larger than the carrier signal, UP outputs a voltage for turning on the switching element 18a, and UN outputs a voltage for turning off the switching element 18d. On the other hand, when the voltage command value Vu * is smaller than the carrier signal, on the contrary, UP outputs a voltage for turning off the switching element 18a, and UN outputs a voltage for turning on the switching element 18d. The same applies to other signals, and VP and VN are determined by comparing the voltage command value Vv * and the carrier signal, and WP and WN are determined by comparing the voltage command value Vw * and the carrier signal.
In the case of a general inverter, since the complementary PWM method is adopted, UP and UN, VP and VN, and WP and WN are in opposite relations. Therefore, there are eight switching patterns in total, and the inverter outputs a voltage by combining the eight switching patterns.

  In addition to the equations (1) to (3), the voltage command values Vu *, Vv *, and Vw * may be obtained by two-phase modulation, third-order harmonic superposition modulation, space vector modulation, or the like.

Next, the operation of the inverter control unit 11 will be described.
FIG. 3 is a flowchart showing the operation of the inverter control unit 11.
(S1: heating judgment step)
The compressor heating permission unit 12 determines whether or not the liquid refrigerant is in the compressor 1 while the operation of the compressor 1 is stopped.
If it is determined that the liquid refrigerant is in the compressor 1 (YES in S1), the process proceeds to S2, and a preheating PWM signal is generated. On the other hand, when it is determined that the liquid refrigerant does not stay in the compressor 1 (NO in S1), it is determined again whether the liquid refrigerant stays in the compressor 1 after a predetermined time has elapsed.
(S2: Voltage command value generation step)
The high-frequency AC voltage generator 13 integrates the rotational speed command ω * output from the rotational speed command output unit 15 by the integrator 14 to obtain a voltage phase command θ. Then, the high-frequency AC voltage generator 13 uses the voltage phase command θ and the amplitude A output by the amplitude output unit 16 to use the voltage command values Vu *, Vv *, Vw * is calculated and output to the PWM signal generator 17.
(S3: PWM signal generation step)
The PWM signal generation unit 17 compares the voltage command values Vu *, Vv *, and Vw * output from the high-frequency AC voltage generation unit 13 with the carrier signal to obtain the PWM signals UP, VP, WP, UN, VN, and WN. Output to the inverter 9. As a result, the switching elements 18 a to 18 f of the inverter 9 are driven to apply a high frequency voltage to the motor 8.
By applying a high frequency voltage to the motor 8, the motor 8 is efficiently heated by the iron loss of the motor 8 and the copper loss generated by the current flowing through the winding. When the motor 8 is heated, the liquid refrigerant staying in the compressor 1 is heated and vaporized, and leaks to the outside of the compressor 1.
(S4: End determination step)
The compressor heating permission unit 12 determines whether the refrigerant has leaked from the compressor 1.
When the refrigerant has leaked (YES in S4), it is determined that the refrigerant has returned to the normal state, and the voltage application to the motor 8 is terminated. On the other hand, if the refrigerant has not leaked (NO in S4), the process returns to (S2) to continue generating the preheating PWM signal.

In S <b> 1, a method will be described in which the compressor heating permission unit 12 determines whether or not the liquid refrigerant is in the compressor 1.
Generally, the state in which the liquid refrigerant stays in the compressor 1 occurs when the temperature of the compressor 1 is the lowest among the devices constituting the refrigeration cycle. The compressor 1 is made of metal and has the largest heat capacity in the refrigeration cycle and the temperature change is slow. Therefore, when the outside air temperature rises, the compressor 1 has a slower temperature rise than other devices constituting the refrigeration cycle. Therefore, when the outside air temperature rises and a little time elapses, the compressor 1 becomes lower in temperature than the other devices, and the liquid refrigerant stays in the compressor 1. Therefore, the compressor heating permission unit 12 may detect or estimate this state and heat the compressor.

For example, the compressor heating permission unit 12 determines that the liquid refrigerant is in the compressor 1 when the outside air temperature rises by a predetermined temperature or more compared to a predetermined time before. The compressor heating permission unit 12 compares the temperature of the equipment other than the compressor 1 constituting the refrigeration cycle and the outside air temperature with the temperature of the compressor 1, and when the temperature of the compressor 1 is low, It may be determined that the liquid refrigerant is in the state 1. Furthermore, since the temperature of the compressor 1 becomes the lowest among the devices constituting the refrigeration cycle from the early morning to the day when the temperature rises, the compressor heating permission unit 12 causes the liquid refrigerant to enter the compressor 1 from the early morning to the day. You may judge that it is the state which stayed.
As described above, when the compressor heating permission unit 12 determines that the liquid refrigerant is in the state of being retained in the compressor 1, the liquid refrigerant can be reliably heated by heating the compressor 1 and consumed. Electric power can be reduced.

  Further, in consideration of a case where the compressor heating permission unit 12 cannot correctly determine the state in which the liquid refrigerant has accumulated in the compressor 1 due to a detection error, a predetermined time (for example, after the operation of the compressor 1 is stopped) A voltage may be applied every time 12 hours). As a result, it is possible to suppress compressor destruction due to liquid refrigerant compression and motor burn-in due to dilution of lubricating oil.

The rotation speed command ω * output from the rotation speed command output unit 15 in S2 will be described.
If a high frequency voltage equal to or higher than the operating frequency during the compression operation is applied to the motor 8, the rotor in the motor 8 cannot follow the frequency, and rotation and vibration are not generated. Therefore, in S2, the rotation speed command output unit 15 may output a rotation speed command ω * that is equal to or higher than the operation frequency during the compression operation.
In general, the operating frequency during the compression operation is at most 1 kHz. Therefore, a high frequency voltage of 1 kHz or higher may be applied to the motor 8. Moreover, if a high frequency voltage of 14 kHz or higher is applied to the motor 8, the vibration sound of the iron core of the motor 8 approaches the upper limit of the audible frequency, which is effective in reducing noise. Therefore, for example, the rotation speed command output unit 15 outputs a rotation speed command ω * that provides a high frequency voltage of about 20 kHz.

  However, if the frequency of the high-frequency voltage exceeds the maximum rated frequency of the switching elements 18a to 18f, a load or a power supply short circuit due to the destruction of the switching elements 18a to 18f may occur, resulting in smoke or fire. Therefore, in order to ensure reliability, it is desirable that the frequency of the high frequency voltage be not more than the maximum rated frequency.

The amplitude A output from the amplitude output unit 16 in S2 will be described.
Depending on the magnitude of the amplitude A, the heating amount can be adjusted. The required heating amount varies depending on the size of the compressor 1 and environmental conditions such as the outside air temperature.
Here, the size of the compressor 1 is determined at the time of product shipment. Therefore, a rough range of the amplitude A can be determined according to the size of the compressor 1 at the time of product shipment. Environmental conditions vary depending on the location, time, and time of installation. Therefore, a rough range of the amplitude A determined according to the size of the compressor 1 at the time of product shipment is stored in the storage device. The amplitude output unit 16 measures the outside air temperature and the like with a temperature sensor, and controls the magnitude of the amplitude A to be output within a range determined at the time of product shipment according to the measured environmental conditions such as the outside air temperature.

In S4, the method by which the compressor heating permission unit 12 determines whether the refrigerant has leaked will be described.
As described above, when the temperature of the compressor is the lowest among the devices constituting the refrigeration cycle, the liquid refrigerant stays in the compressor 1. Conversely, if the temperature of the compressor 1 is not the lowest among the devices constituting the refrigeration cycle, the refrigerant leaks.
Therefore, for example, the compressor heating permission unit 12 compares the temperature of the equipment other than the compressor 1 constituting the refrigeration cycle or the outside air temperature with the temperature of the compressor 1, and the temperature of the compressor 1 is different from that of the other equipment. When the state higher than the outside air temperature continues for a predetermined time or more, it is determined that the refrigerant has leaked.

  As described above, in the heat pump device 100 according to the first embodiment, when the liquid refrigerant stays in the compressor 1, the high-frequency voltage is applied to the motor 8. The motor 8 can be heated. Thereby, the refrigerant staying in the compressor 1 can be efficiently heated, and the staying refrigerant can be leaked to the outside of the compressor 1.

In recent years, motors of compressors for heat pump devices are widely used for high efficiency, such as motors with an IPM structure and concentrated winding motors with small coil ends and low winding resistance. Since the concentrated winding motor has a small winding resistance and a small amount of heat generated by copper loss, a large amount of current needs to flow through the winding. When a large amount of current is passed through the windings, the current flowing through the inverter 9 also increases and the inverter loss increases.
Therefore, when heating is performed by applying the above-described high frequency voltage, an inductance component due to a high frequency is increased, and the winding impedance is increased. Therefore, although the current flowing through the winding is reduced and the copper loss is reduced, the iron loss due to the application of the high frequency voltage is generated and heating can be performed effectively. Furthermore, since the current flowing through the winding is reduced, the current flowing through the inverter is also reduced, the loss of the inverter 9 can be reduced, and more efficient heating is possible.
Further, when heating is performed by applying the high-frequency voltage described above, when the compressor is an IPM motor, the rotor surface where the high-frequency magnetic flux is linked also becomes a heat generating portion. For this reason, an increase in the refrigerant contact surface and rapid heating of the compression mechanism are realized, so that the refrigerant can be efficiently heated.

In addition, the switching elements 18a to 18f constituting the inverter 9 and the diode elements connected in parallel to the switching elements 18a to 18f generally use a semiconductor made of silicon (Si). However, instead of this, a wide gap semiconductor made of silicon carbide (SiC), gallium nitride (GaN), or diamond may be used.
A switching element or a diode element formed of such a wide band gap semiconductor has a high withstand voltage and a high allowable current density. Therefore, the switching element and the diode element can be reduced in size, and by using these reduced switching element and diode element, the semiconductor module incorporating these elements can be reduced in size.
Moreover, the switching element and the diode element formed by such a wide band gap semiconductor have high heat resistance. As a result, the heat sink fins of the heat sink can be miniaturized and the water cooling part can be air cooled, so that the semiconductor module can be further miniaturized.
Furthermore, switching elements and diode elements formed of such a wide band gap semiconductor have low power loss. For this reason, it is possible to increase the efficiency of the switching element and the diode element, and to increase the efficiency of the semiconductor module.

  Although both the switching element and the diode element are preferably formed of a wide bandgap semiconductor, either one of the elements may be formed of a wide bandgap semiconductor, and the effects described in this embodiment are achieved. Can be obtained.

  In addition, a similar effect can be obtained by using a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) having a super junction structure, which is known as a highly efficient switching element.

  Moreover, it is difficult for the compressor of the scroll mechanism to perform high-pressure relief of the compression chamber. Therefore, compared to other types of compressors, when liquid compression is performed, there is a high possibility that the compression mechanism will be overstressed and damaged. However, in the heat pump device 100 of the first embodiment, the compressor can be heated efficiently, and the liquid refrigerant in the compressor can be prevented from staying. Therefore, since liquid compression can be prevented, it is effective even when a scroll compressor is used as the compressor 1.

  Furthermore, in the case of a heating device having a frequency of 10 kHz and an output exceeding 50 W, there may be restrictions imposed by laws and regulations. For this reason, the amplitude of the voltage command value may be adjusted in advance so as not to exceed 50 W, or the feedback control may be performed so that the flowing current or voltage is detected to be 50 W or less.

Embodiment 2. FIG.
In Embodiment 2, a method for generating a high-frequency voltage will be described.

In the case of a general inverter, the upper limit of the carrier frequency that is the frequency of the carrier signal is determined by the switching speed of the switching element of the inverter. In the case of a general IGBT (Insulated Gate Bipolar Transistor), the upper limit of the switching speed is about 20 kHz. For this reason, it is difficult to output a high-frequency voltage equal to or higher than the carrier frequency that is a carrier wave.
Further, when the frequency of the high frequency voltage is about 1/10 of the carrier frequency, the waveform output accuracy of the high frequency voltage is deteriorated, and there is a risk that a direct current component is superimposed. Considering this point, when the carrier frequency is set to 20 kHz, if the frequency of the high frequency voltage is set to 2 kHz, which is 1/10 of the carrier frequency, the frequency of the high frequency voltage becomes an audible frequency region, and there is a concern about noise deterioration.

FIG. 4 is a diagram illustrating a configuration of the heat pump device 100 according to the second embodiment.
The heat pump apparatus 100 in the second embodiment is the same as the heat pump apparatus 100 in the first embodiment shown in FIG. 1 except that it includes a phase switching unit 19 instead of the integrator 14 and the rotation speed command output unit 15. For this reason, the same reference numerals are used and description thereof is omitted, and only the changes are described.

In the first embodiment, the rotational speed command ω * is integrated by the integrator 14 to obtain the phase θ of the voltage command value. On the other hand, in the second embodiment, the phase switching unit 19 alternately switches two types of phases, ie, the phase θ1 and the phase θ2 that is approximately 180 degrees different from the phase θ1, to obtain the phase of the voltage command value.
In the following description, it is assumed that θ1 = 0 [degree] and θ2 = 180 [degree].

Next, the operation of the inverter control unit 11 will be described.
Since the operation is the same as that of the inverter control unit 11 in the first embodiment except for the operation of S2 shown in FIG.
In S2, the phase switching unit 19 alternately switches between the phase θ1 and the phase θ2 at the timing of the top (peak) or bottom (valley) of the carrier signal, or at the timing of the top and bottom, The phase θ is output to the high-frequency AC voltage generator 13. The high-frequency AC voltage generation unit 13 uses the voltage phase command θ and the amplitude A output from the amplitude output unit 16 to calculate the voltage command values Vu *, Vv *, Vw * using the equations (1) to (3). Is output to the PWM signal generation unit 17.
The phase switching unit 19 switches the phase θ1 and the phase θ2 at the timing of the peak (peak) or valley (bottom), peak, and valley of the carrier signal, so that a PWM signal synchronized with the carrier signal can be output. Become.

FIG. 5 is a timing chart when the phase switching unit 19 alternately switches between the phase θ1 and the phase θ2 at the top and bottom timings of the carrier signal. It should be noted that UP and UN, VP and VN, and WP and WN are on / off states opposite to each other, and if one is known, the other is also known, so only UP, VP, and WP are shown here.
As shown in FIG. 5, the PWM signal changes, and the voltage vectors are V0 (UP = VP = WP = 0), V4 (UP = 1, VP = WP = 0), V7 (UP = VP = WP = 1), It changes in the order of V3 (UP = 0, VP = WP = 1), V0 (UP = VP = WP = 0),.

FIG. 6 is an explanatory diagram of changes in the voltage vector shown in FIG. In FIG. 6, the switching element 18 surrounded by a broken line is turned on, and the switching element 18 not surrounded by a broken line is turned off.
As shown in FIG. 6, no current flows when the V0 vector and the V7 vector are applied. In addition, when the V4 vector is applied, a current in the U-phase direction (current of + Iu) flows into the motor 8 via the U phase and flows out of the motor 8 via the V phase and the W phase. The current in the −U phase direction (current of −Iu) flowing into the motor 8 through the phase and the W phase and flowing out of the motor 8 through the U phase flows in the winding of the motor 8. That is, a current in the reverse direction flows through the winding of the motor 8 when the V4 vector is applied and when the V3 vector is applied. Since the voltage vector changes in the order of V0, V4, V7, V3, V0,..., + Iu current and −Iu current flow alternately in the winding of the motor 8. In particular, as shown in FIG. 5, since the V4 vector and the V3 vector appear during one carrier period (1 / fc), an AC voltage synchronized with the carrier frequency fc can be applied to the winding of the motor 8. It becomes.
Further, since the V4 vector (+ Iu current) and the V3 vector (−Iu current) are alternately output, the forward and reverse torques are instantaneously switched. Therefore, it is possible to apply a voltage that suppresses the vibration of the rotor by canceling the torque.

FIG. 7 is a timing chart when the phase switching unit 19 switches the phase θ1 and the phase θ2 alternately at the bottom timing of the carrier signal.
As shown in FIG. 7, the PWM signal changes, and the voltage vector changes in the order of V0, V4, V7, V7, V3, V0, V0, V3, V7, V7, V4, V0,. Since the V4 vector and the V3 vector appear during a two-carrier cycle, an AC voltage having a ½ carrier frequency can be applied to the winding of the motor 8.

  As described above, in the heat pump device 100 according to the second embodiment, the voltage command value is switched alternately between the two phases of the phase θ1 and the phase θ2 that is approximately 180 degrees different from the phase θ1 in synchronization with the carrier signal. Of the phase. Thereby, a high frequency voltage synchronized with the carrier frequency can be applied to the winding of the motor 8.

Embodiment 3 FIG.
In the third embodiment, a method of making the heating amount constant even in the case of an IPM motor will be described.

FIG. 8 is an explanatory diagram of the rotor position (rotor stop position) of the IPM motor. Here, the rotor position φ of the IPM motor is represented by the magnitude of the angle at which the direction of the N pole of the rotor deviates from the U-phase direction.
FIG. 9 is a diagram illustrating a change in current depending on the rotor position. In the case of an IPM motor, the winding inductance depends on the rotor position. Therefore, the winding impedance represented by the product of the electrical angular frequency ω and the inductance value varies according to the rotor position. Therefore, even when the same voltage is applied, the current flowing through the winding of the motor 8 fluctuates and the amount of heating changes.

FIG. 10 is a diagram illustrating a configuration of the heat pump apparatus 100 according to the third embodiment.
The heat pump apparatus 100 in the third embodiment is the same as the heat pump apparatus 100 in the second embodiment shown in FIG. 4 except that an adder 20 (addition unit) is added. For this reason, the same reference numerals are used and description thereof is omitted, and only the changes are described.

  In the second embodiment, the phase switching unit 19 alternately switches the two types of phases θ1 and θ2 to the phase of the voltage command value, so that the AC voltage of the carrier frequency or 1/2 carrier frequency is converted to the motor. Applied to 8 windings. In this case, the energization phase is limited to two of the phase θ1 and the phase θ2 having a phase difference of 180 degrees with respect to the phase θ1. Therefore, even when the same voltage is applied, the current flowing through the winding of the motor 8 varies depending on the rotor position, and the amount of heating changes. As a result, depending on the rotor position, a large amount of electric power may be consumed in order to obtain a necessary heating amount.

Next, the operation of the inverter control unit 11 will be described.
Since the operation is the same as that of the inverter control unit 11 in the first and second embodiments except for the operation of S2 shown in FIG.
In S2, the phase switching unit 19 alternately switches and outputs the phase θ1 and the phase θ2 at the top or bottom timing of the carrier signal or at the top and bottom timings. The adder 20 adds the phase change component θplus that changes over time to the phase output by the phase switching unit 19 to obtain the phase θ3, and outputs the phase θ3 as the voltage phase command θ to the high-frequency AC voltage generation unit 13. . The high-frequency AC voltage generation unit 13 uses the voltage phase command θ and the amplitude A output from the amplitude output unit 16 to calculate the voltage command values Vu *, Vv *, Vw * using the equations (1) to (3). Is output to the PWM signal generation unit 17.
By adding the phase change component θplus to the phases θ1 and θ2 by the adder 18 and changing the phase of the voltage command value over time, the compressor 1 can be heated uniformly regardless of the rotor position.

FIG. 11 is a diagram illustrating an applied voltage when θplus is changed over time.
Here, θplus is changed by 45 degrees as time passes, 0 degrees, 45 degrees, 90 degrees, 135 degrees,. If θplus is 0 degrees, the phase θ of the voltage command value is 0 degrees and 180 degrees, and if θplus is 45 degrees, the phase θ of the voltage command value is 45 degrees and 225 degrees, and θplus is 90 degrees. For example, the phase θ of the voltage command value is 90 degrees and 270 degrees, and if θplus is 135 degrees, the phase θ of the voltage command value is 135 degrees and 315 degrees.
That is, first, θplus is set to 0 degrees, and the phase θ of the voltage command value is switched between 0 degrees and 180 degrees in synchronization with the carrier signal for a predetermined time. Thereafter, θplus is switched to 45 degrees, and the phase θ of the voltage command value is switched between 45 degrees and 225 degrees in synchronization with the carrier signal for a predetermined time. Then, θplus is switched to 90 degrees, and so on at predetermined time intervals, such as 0 degrees and 180 degrees, 45 degrees and 225 degrees, 90 degrees and 270 degrees, 135 degrees and 315 degrees,. And the phase θ of the voltage command value are switched.
As a result, the energization phase of the high-frequency AC voltage changes with time, so that the compressor 1 can be heated uniformly regardless of the rotor position.

FIG. 12 is an explanatory diagram of the intermediate voltage. The intermediate voltage is a voltage having a phase different from the direction of each phase (U phase, -U phase, V phase, -V phase, W phase, -W phase).
The inverter 9 can only perform switching of 8 patterns of V0 to V7. Therefore, when the energization phase is switched as shown in FIG. 11, for example, when θplus is 45 degrees, the intermediate voltage shown in FIG. 12 is created by the voltage vectors of V4 and V6 or V3 and V1.
Similarly, when θplus is 90 degrees other than 45 degrees, 135 degrees, or the like, an intermediate voltage is similarly generated by two voltage vectors.

FIG. 13 is a timing chart when θplus is 45 degrees when the phase switching unit 19 switches the phase θ1 and the phase θ2 alternately at the timing of the top and bottom of the carrier signal.
As shown in FIG. 13, two voltage vectors (V4 and V6, or V3 and V1) are output between V0 and V7. In this manner, the above-described intermediate voltage is created by outputting two different voltage vectors between V0 and V7.

FIG. 14 is a diagram showing the current flowing in each phase of the UVW of the motor when θplus is 0 degree (the U phase (V4) direction is 0 degree), 30 degrees, and 60 degrees.
When θplus is 0 degree, as shown in FIG. 5, another voltage vector (one positive voltage side and two negative voltage sides of switching elements 18a to 18f, or two positive voltage sides) is provided between V0 and V7. And only one negative voltage side voltage vector is generated. In this case, the current waveform has a trapezoidal shape and has a low harmonic component.
However, when θplus is 30 degrees, two different voltage vectors are generated between V0 and V7 as shown in FIG. In this case, the current waveform is distorted, resulting in a current with many harmonic components. This distortion of the current waveform may cause adverse effects such as motor noise and motor shaft vibration.
Also, when θplus is 60 degrees, only one other voltage vector is generated between V0 and V7, similarly to the case where θplus is 0 degrees. In this case, the current waveform is trapezoidal, and the current has less harmonic components.

As described above, if the voltage on the hexagonal diagonal line shown in FIG. 12 is output, only one other voltage vector is output between the voltage vectors V0 and V7 which are zero vectors, and distortion of the current waveform can be reduced. . Therefore, if θplus is a value of n times 60 degrees (n is an integer of 0 or more), motor noise and motor shaft vibration due to current waveform distortion reduction can be suppressed.
Therefore, for example, θplus may be changed every 60 degrees or 120 degrees, which is a phase n times 60 degrees, every predetermined time. However, since it is necessary to prevent the heating amount from changing depending on the stop position of the rotor, it is meaningless to change θplus by 180 degrees. That is, it is necessary to change θplus by 60 degrees or 120 degrees, for example, which can make the current uniform.

  Note that when an arithmetic processing unit represented by a microcomputer is used, 60 degrees cannot be realized accurately due to quantization, and a slight deviation may occur. In this case, the processing by the microcomputer may be limited so as not to output a voltage vector whose output is small (output time is short) of the two voltage vectors.

Here, as shown in FIG. 15, when θplus is changed, the energization phase changes abruptly. Therefore, the current flowing through the motor 8 changes abruptly and pulsation or the like occurs. For this reason, when θplus is changed, there is a possibility that motor noise or motor shaft vibration may occur.
Therefore, as shown in FIG. 16, the amplitude output unit 16 gradually decreases the amplitude A immediately before the change of θplus, and gradually increases the amplitude A immediately after the change of θplus. For example, the amplitude output unit 16 gradually decreases the amplitude A immediately before the change of θplus so that the amplitude becomes 0 at the change timing of θplus, and returns the amplitude A to the original size immediately after the change of θplus. . As a result, as shown in FIG. 17, since the current value at the timing of changing θplus becomes small, it is possible to suppress a sudden change in the current flowing through the motor.
Note that the amplitude output unit 16 may decrease the amplitude A at a time immediately before the change of θplus, and gradually increase the amplitude A immediately after the change of θplus.

FIG. 18 is a diagram showing a drive circuit 21 that receives the PWM signal from the PWM signal generation unit 17 and drives each switching element 18 of the inverter 9. Here, for the sake of simplicity, only the U-phase drive circuit 21 that drives the switching elements 18a and 18d is shown. Actually, a drive circuit having the same configuration as that of the drive circuit 21 shown in FIG. 18 is also provided in the V phase and the W phase.
The drive circuit 21 includes a charge pump circuit 26, a negative voltage side switching element drive circuit 27, and a positive voltage side switching element drive circuit 28.
The charge pump circuit 26 is configured by sequentially connecting a switching power supply 22, a resistor 23, a diode 24, and a capacitor 25. The end of the charge pump circuit 26 on the switching power supply 22 side is connected to the negative voltage side of the inverter 9, and the end of the charge pump circuit 26 on the capacitor 25 side is the positive voltage side of the U-phase series connection circuit in the inverter 9. The switching element 18a and the negative voltage side switching element 18d are connected.
The negative voltage side switching element drive circuit 27 is connected between the switching power supply 22 and the resistor 23 of the charge pump circuit 26. The negative voltage side switching element driving circuit 27 receives the PWM signal UN from the PWM signal generation unit 17 and drives the negative voltage side switching element 18d of the inverter 9 when the voltage UN turns on.
The positive voltage side switching element driving circuit 28 is connected between the diode 24 of the charge pump circuit 26 and the capacitor 25. The positive voltage side switching element drive circuit 28 receives the PWM signal UP from the PWM signal generation unit 17 and drives the positive voltage side switching element 18a of the inverter 9 when UP is a voltage to be turned on.

The negative voltage side switching element driving circuit 27 and the positive voltage side switching element driving circuit 28 need to be driven by separate power sources. Here, the negative voltage side switching element drive circuit 27 is driven by the switching power supply 22, and the positive voltage side switching element drive circuit 28 is driven by the voltage charged in the capacitor 25.
Here, as described above, when the amplitude output unit 16 changes the amplitude to 0 when θplus changes and is not energized, the voltage charged in the capacitor 25 decreases. Therefore, there is a possibility that the switching element 18a cannot be normally driven by the positive voltage side switching element driving circuit 28.
Accordingly, as shown in FIG. 19, every time θplus changes, the negative voltage side switching element drive circuit 27 is driven to generate a charge pulse. Then, the voltage is charged in the capacitor 25 through the path indicated by the arrow in FIG. 18, and a power source for driving the positive voltage side switching element driving circuit 28 is secured. As a result, it is possible to normally drive the positive voltage side switching element drive circuit 28 and to reduce failures and problems.

As described above, in the heat pump device 100 according to the third embodiment, the phase of the voltage command value is obtained by adding the phase change component θplus that changes over time to the phase output by the phase switching unit 19. As a result, the energization phase of the high-frequency AC voltage changes with time, so that the compressor 1 can be heated uniformly regardless of the rotor position.
In particular, in the heat pump apparatus 100 according to Embodiment 3, the phase change component θplus is set to n times 60 degrees. Thereby, distortion of a current waveform can be reduced, and motor noise, motor shaft vibration, and the like can be suppressed.

Embodiment 4 FIG.
In the fourth embodiment, an example of a circuit configuration of the heat pump device 100 will be described.
For example, in FIG. 1 and the like, the heat pump device 100 in which the compressor 1, the four-way valve 2, the heat exchanger 3, the expansion mechanism 4, and the heat exchanger 5 are sequentially connected by piping is illustrated. In the fourth embodiment, a heat pump device 100 having a more specific configuration will be described.

FIG. 20 is a circuit configuration diagram of the heat pump device 100 according to the fourth embodiment.
FIG. 21 is a Mollier diagram of the refrigerant state of the heat pump apparatus 100 shown in FIG. In FIG. 21, the horizontal axis represents specific enthalpy and the vertical axis represents refrigerant pressure.
In the heat pump device 100, a compressor 31, a heat exchanger 32, an expansion mechanism 33, a receiver 34, an internal heat exchanger 35, an expansion mechanism 36, and a heat exchanger 37 are sequentially connected by piping, and a refrigerant Is provided with a main refrigerant circuit. In the main refrigerant circuit 38, a four-way valve 39 is provided on the discharge side of the compressor 31, and the circulation direction of the refrigerant can be switched. A fan 40 is provided in the vicinity of the heat exchanger 37. The compressor 31 is the compressor 1 described in the above embodiment, and includes the motor 8 driven by the inverter 9 and the compression mechanism 7.
Furthermore, the heat pump apparatus 100 includes an injection circuit 42 that connects between the receiver 34 and the internal heat exchanger 35 to the injection pipe of the compressor 31 by piping. An expansion mechanism 41 and an internal heat exchanger 35 are sequentially connected to the injection circuit 42.
A water circuit 43 through which water circulates is connected to the heat exchanger 32.

  First, the operation | movement at the time of the heating operation of the heat pump apparatus 100 is demonstrated. During the heating operation, the four-way valve 39 is set in the solid line direction. The heating operation includes not only heating used for air conditioning, but also hot water supply that heats water to make hot water.

The gas-phase refrigerant (point 1 in FIG. 21) that has become high-temperature and high-pressure in the compressor 31 is discharged from the compressor 31, and is heat-exchanged and liquefied by a heat exchanger 32 that is a condenser and a radiator (FIG. 21). Point 2). At this time, the water circulating through the water circuit 43 is warmed by the heat radiated from the refrigerant and used for heating and hot water supply.
The liquid-phase refrigerant liquefied by the heat exchanger 32 is decompressed by the expansion mechanism 33 and becomes a gas-liquid two-phase state (point 3 in FIG. 21). The refrigerant in the gas-liquid two-phase state by the expansion mechanism 33 is heat-exchanged with the refrigerant sucked into the compressor 31 by the receiver 34, cooled, and liquefied (point 4 in FIG. 21). The liquid-phase refrigerant liquefied by the receiver 34 branches and flows into the main refrigerant circuit 38 and the injection circuit 42.
The liquid phase refrigerant flowing through the main refrigerant circuit 38 is heat-exchanged by the internal heat exchanger 35 with the refrigerant flowing through the injection circuit 42 that has been decompressed by the expansion mechanism 41 and is in a gas-liquid two-phase state, and further cooled (FIG. 21). Point 5). The liquid-phase refrigerant cooled by the internal heat exchanger 35 is decompressed by the expansion mechanism 36 and becomes a gas-liquid two-phase state (point 6 in FIG. 21). The refrigerant that has been in the gas-liquid two-phase state by the expansion mechanism 36 is heated and exchanged with the outside air by the heat exchanger 37 serving as an evaporator (point 7 in FIG. 21). The refrigerant heated by the heat exchanger 37 is further heated by the receiver 34 (point 8 in FIG. 21) and sucked into the compressor 31.
On the other hand, as described above, the refrigerant flowing through the injection circuit 42 is decompressed by the expansion mechanism 41 (point 9 in FIG. 21) and is heat-exchanged by the internal heat exchanger 35 (point 10 in FIG. 21). The gas-liquid two-phase refrigerant (injection refrigerant) heat-exchanged by the internal heat exchanger 35 flows into the compressor 31 from the injection pipe of the compressor 31 in the gas-liquid two-phase state.
In the compressor 31, the refrigerant (point 8 in FIG. 21) sucked from the main refrigerant circuit 38 is compressed and heated to an intermediate pressure (point 11 in FIG. 21). The refrigerant that has been compressed and heated to the intermediate pressure (point 11 in FIG. 21) joins the injection refrigerant (point 10 in FIG. 21), and the temperature drops (point 12 in FIG. 21). And the refrigerant | coolant (point 12 of FIG. 21) in which temperature fell is further compressed and heated, becomes high temperature high pressure, and is discharged (point 1 of FIG. 21).

When the injection operation is not performed, the opening degree of the expansion mechanism 41 is fully closed. That is, when the injection operation is performed, the opening degree of the expansion mechanism 41 is larger than the predetermined opening degree. However, when the injection operation is not performed, the opening degree of the expansion mechanism 41 is larger than the predetermined opening degree. Make it smaller. Thereby, the refrigerant does not flow into the injection pipe of the compressor 31.
Here, the opening degree of the expansion mechanism 41 is controlled by electronic control by a control unit such as a microcomputer.

  Next, the operation | movement at the time of the cooling operation of the heat pump apparatus 100 is demonstrated. During the cooling operation, the four-way valve 39 is set in the direction of the broken line. The cooling operation includes not only cooling used for air conditioning but also making cold water by taking heat from water, freezing and the like.

The gas-phase refrigerant (point 1 in FIG. 21) that has become high-temperature and high-pressure in the compressor 31 is discharged from the compressor 31, and is heat-exchanged and liquefied in a heat exchanger 37 that is a condenser and a radiator (FIG. 21). Point 2). The liquid-phase refrigerant liquefied by the heat exchanger 37 is depressurized by the expansion mechanism 36 and becomes a gas-liquid two-phase state (point 3 in FIG. 21). The refrigerant in the gas-liquid two-phase state by the expansion mechanism 36 is heat-exchanged by the internal heat exchanger 35, cooled and liquefied (point 4 in FIG. 21). In the internal heat exchanger 35, the refrigerant that has become a gas-liquid two-phase state by the expansion mechanism 36 and the liquid-phase refrigerant that has been liquefied by the internal heat exchanger 35 have been decompressed by the expansion mechanism 41, and have become a gas-liquid two-phase state. Heat is exchanged with the refrigerant (point 9 in FIG. 21). The liquid refrigerant (the point 4 in FIG. 21) heat-exchanged by the internal heat exchanger 35 branches and flows into the main refrigerant circuit 38 and the injection circuit 42.
The liquid-phase refrigerant flowing through the main refrigerant circuit 38 is heat-exchanged with the refrigerant sucked into the compressor 31 by the receiver 34 and further cooled (point 5 in FIG. 21). The liquid-phase refrigerant cooled by the receiver 34 is decompressed by the expansion mechanism 33 and becomes a gas-liquid two-phase state (point 6 in FIG. 21). The refrigerant in the gas-liquid two-phase state by the expansion mechanism 33 is heat-exchanged and heated by the heat exchanger 32 serving as an evaporator (point 7 in FIG. 21). At this time, when the refrigerant absorbs heat, the water circulating in the water circuit 43 is cooled and used for cooling and freezing.
Then, the refrigerant heated by the heat exchanger 32 is further heated by the receiver 34 (point 8 in FIG. 21) and sucked into the compressor 31.
On the other hand, as described above, the refrigerant flowing through the injection circuit 42 is decompressed by the expansion mechanism 41 (point 9 in FIG. 21) and is heat-exchanged by the internal heat exchanger 35 (point 10 in FIG. 21). The gas-liquid two-phase refrigerant (injection refrigerant) heat-exchanged by the internal heat exchanger 35 flows from the injection pipe of the compressor 31 in the gas-liquid two-phase state.
The compression operation in the compressor 31 is the same as in the heating operation.

  When the injection operation is not performed, the opening of the expansion mechanism 41 is fully closed so that the refrigerant does not flow into the injection pipe of the compressor 31 as in the heating operation.

In the above description, the heat exchanger 32 has been described as a heat exchanger such as a plate heat exchanger that exchanges heat between the refrigerant and the water circulating in the water circuit 43. The heat exchanger 32 is not limited to this and may exchange heat between the refrigerant and the air.
The water circuit 43 may be a circuit in which other fluid circulates instead of a circuit in which water circulates.

  As described above, the heat pump device 100 can be used in a heat pump device using an inverter compressor such as an air conditioner, a heat pump water heater, a refrigerator, or a refrigerator.

  DESCRIPTION OF SYMBOLS 1 Compressor, 2 Four way valve, 3 Heat exchanger, 4 Expansion mechanism, 5 Heat exchanger, 6 Refrigerant piping, 7 Compression mechanism, 8 Motor, 9 Inverter, 10 Bus voltage detection part, 11 Inverter control part, 12 Compressor Heating permission unit, 13 high frequency AC voltage generation unit, 14 integrator, 15 rotation speed command output unit, 16 amplitude output unit, 17 PWM signal generation unit, 18 switching element, 19 phase switching unit, 20 adder, 21 drive circuit, 22 switching power supply, 23 resistor, 24 diode, 25 capacitor, 26 charge pump circuit, 27 negative voltage side switching element driving circuit, 28 positive voltage side switching element driving circuit, 31 compressor, 32, 37 heat exchanger, 33, 36 41 Expansion mechanism 34 Receiver 35 Internal heat exchanger 38 Main refrigerant circuit 39 Four-way valve 40 Down, 42 injection circuit, 43 water circuit, 100 a heat pump apparatus.

The heat pump apparatus according to the present invention, a compressor having a compression mechanism for compressing a refrigerant, a motor for operating said compression mechanism, wherein the compressor has a Louis converter to apply a predetermined voltage to the motor, before Symbol includes an inverter control unit for controlling the inverter, wherein the inverter control unit in synchronization with the high frequency reference signal than the operating frequency during the compression operation of the motor, the position phase of the voltage command value of the inverter a phase switching unit for switching and outputting, by changing the value n is an integer of 0 or more predetermined time intervals, the output position phase pressurized El addition unit of the phase change section 60 degrees n times phase θplus When an amplitude output section for outputting the amplitude of the voltage command value, based on the output amplitude of the output position phase and the amplitude output of the adding unit, the voltage generating unit that generates and outputs a voltage command value of the inverter When Characterized in that it comprises a driving signal generation unit for generating a drive signal of the inverter based on the voltage command value.

Claims (15)

A compressor having a compression mechanism for compressing the refrigerant;
A motor for operating the compression mechanism of the compressor;
A three-phase inverter that applies a predetermined voltage to the motor, and a three-phase inverter that is configured by connecting a series connection circuit of two switching elements in parallel for three phases; and
An inverter control unit for controlling the three-phase inverter;
The inverter control unit
A phase switching unit that switches and outputs a phase θ1 and a phase θ2 that is substantially 180 degrees different from the phase θ1 in synchronization with a reference signal having a predetermined frequency;
An adder that outputs a phase θ3 by changing a value n that is an integer greater than or equal to 0 every predetermined time, and adding a phase θplus of n times 60 degrees to the phase output by the phase switching unit;
A voltage generator that generates and outputs three-phase voltage command values Vu *, Vv *, and Vw * based on the phase θ3 output from the adder;
The three-phase voltage command values Vu *, Vv *, Vw * output from the voltage generator are compared with the reference signal to generate six drive signals corresponding to the switching elements of the three-phase inverter, A heat pump device comprising: a drive signal generation unit that generates a high-frequency AC voltage in the three-phase inverter by outputting each generated drive signal to a corresponding switching element of the three-phase inverter. The drive signal generator is
While outputting a drive signal in which one of the two switching elements in each series connection circuit of the three-phase inverter is on and the other is off,
A switching pattern drive signal for turning on one or two switching elements among the switching elements on the positive voltage side of the three-phase inverter is output only in one pattern during a half cycle of the reference signal. The heat pump apparatus according to claim 1. The heat pump device further includes:
An amplitude output unit that outputs an amplitude A having a predetermined width, wherein when the addition unit changes the value n, the amplitude A is reduced, and after the addition unit changes the value n, the amplitude A is gradually increased. Amplitude output unit that increases and returns the original predetermined width to output,
The voltage generator generates three-phase voltage command values Vu *, Vv *, and Vw * based on the phase θ3 output from the adder and the amplitude A output from the amplitude output unit. The heat pump device according to claim 1 or 2. The heat pump device further includes:
For each series connection circuit of the three-phase inverter, comprising a drive circuit for driving the switching element in the series connection circuit,
Each drive circuit
A negative voltage side drive circuit that is driven by the voltage of the switching power supply and drives the switching element on the negative voltage side of the three-phase inverter;
Driving with the voltage of the capacitor charged by driving the negative voltage side drive circuit, the positive voltage side drive circuit for driving the switching element on the positive voltage side of the three-phase inverter,
The said inverter control part drives the said negative voltage side drive circuit and charges the voltage to the said capacitor, when the said addition part changes the value n, The voltage to any one of Claim 1 to 3 characterized by the above-mentioned. The heat pump apparatus as described. 5. The heat pump device according to claim 1, wherein the voltage generator outputs an AC voltage command value having a frequency higher than an operating frequency during the compression operation of the motor. 6. 6. The heat pump device according to claim 1, wherein the phase switching unit switches the phase θ <b> 1 and the phase θ <b> 2 at a timing of at least one of a top and a bottom of the reference signal. . The heat pump device according to any one of claims 1 to 6, wherein the rotor of the motor has an IPM (Interior Permanent Magnet) structure. The inverter control unit further includes:
A detection unit that detects a state in which the outside air temperature has risen above a predetermined temperature compared to a predetermined time ago,
The heat pump device according to any one of claims 1 to 7, wherein the voltage generation unit outputs a voltage command value when the detection unit detects the state. A detection unit that detects that a predetermined time has elapsed when the temperature of the compressor is lower than the outside air temperature;
The heat pump device according to any one of claims 1 to 8, wherein the voltage generation unit outputs a voltage command value when the detection unit detects the state. The heat pump device according to any one of claims 1 to 9, wherein the voltage generator outputs a voltage command value every time a predetermined time elapses after the operation of the compressor is stopped. The heat pump device according to any one of claims 1 to 10, wherein the switching element constituting the inverter is a wide gap semiconductor. The heat pump apparatus according to claim 11, wherein the wide gap semiconductor is any one of SiC, GaN, and diamond. The heat pump device according to any one of claims 1 to 10, wherein the switching element constituting the inverter is a MOSFET having a super junction structure. A heat pump device including a refrigerant circuit in which a compressor, a first heat exchanger, an expansion mechanism, and a second heat exchanger are sequentially connected by piping; and the first heat exchanger connected to the refrigerant circuit. A heat pump system comprising a fluid utilization device that utilizes a fluid heat exchanged with a refrigerant,
The heat pump device is
A compressor having a compression mechanism for compressing the refrigerant;
A motor for operating the compression mechanism of the compressor;
A three-phase inverter that applies a predetermined voltage to the motor, and a three-phase inverter that is configured by connecting a series connection circuit of two switching elements in parallel for three phases; and
An inverter control unit for controlling the three-phase inverter;
The inverter control unit
A phase switching unit that switches and outputs a phase θ1 and a phase θ2 that is substantially 180 degrees different from the phase θ1 in synchronization with a reference signal having a predetermined frequency;
An adder that outputs a phase θ3 by changing a value n that is an integer greater than or equal to 0 every predetermined time, and adding a phase θplus of n times 60 degrees to the phase output by the phase switching unit;
A voltage generator that generates and outputs three-phase voltage command values Vu *, Vv *, and Vw * based on the phase θ3 output from the adder;
The three-phase voltage command values Vu *, Vv *, Vw * output from the voltage generator are compared with the reference signal to generate six drive signals corresponding to the switching elements of the three-phase inverter, A heat pump system comprising: a drive signal generation unit that generates a high-frequency AC voltage in the three-phase inverter by outputting each generated drive signal to a corresponding switching element of the three-phase inverter. A compressor having a compression mechanism for compressing the refrigerant;
A motor for operating the compression mechanism of the compressor;
Control of the three-phase inverter in a heat pump device comprising a three-phase inverter that applies a predetermined voltage to the motor, and a three-phase inverter that is configured by connecting a series connection circuit of two switching elements in parallel for three phases. Is the way
A phase switching step of switching and outputting a phase θ1 and a phase θ2 that is substantially 180 degrees different from the phase θ1 in synchronization with a reference signal of a predetermined frequency;
An addition step of changing a value n, which is an integer greater than or equal to 0, every predetermined time and outputting a phase θ3 obtained by adding a phase θplus of n times 60 degrees to the phase output in the phase switching step;
A voltage generating step of generating and outputting three-phase voltage command values Vu *, Vv *, Vw * based on the phase θ3 output in the adding step;
The three-phase voltage command values Vu *, Vv *, Vw * output in the voltage generation step are compared with the reference signal to generate six drive signals corresponding to the switching elements of the three-phase inverter, A control method for a three-phase inverter, comprising: a drive signal generation step for generating a high-frequency AC voltage in the three-phase inverter by outputting each generated drive signal to a corresponding switching element of the three-phase inverter. .

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